June 2015
Problem of the Month

The Wading Pool

Mr. P needs to fill his grandkids' wading pool with exactly 16 gallons of water.

He has at his disposal a 7-gallon pail, a 5-gallon pail, and water from the faucet.

How can he fill the pool exactly without wasting any water and without removing any water from the pool (water is a precious commodity in Colorado!)?

Solution to the Problem:

Here's one way to do it:

Fill the 7-gallon pail, then use it to fill the 5-gallon pail.

Dump the 2 gallons left in the 7-gallon pail into the pool.

Pour the water from the 5-gallon pail back into the 7-gallon pail.

Go to the faucet and add more water to top off the 7-gallon pail.

Dump those 7 gallons into the pool.

Fill the 7-gallon pail from the faucet and dump them into the pool.

Correctly solved by:

1. Brooks Garris	Lake View High School, Lake View, South Carolina
2. James Alarie	Flint, Michigan
3. Michael Reilly	Silver Spring, Maryland
4. Atul Rai	New Delhi, India

Send any comments or questions to: David Pleacher